*Args and **Kwargs in Python

Let’s know about ** (dual star / asterisk) and * (star / asterisk) are operators in Python. These stars are used in Python for parameters. Args and kwargs are special symbols. These are used to give a variable number of args to function. Special symbol used for passing arguments are keyword arguments and non-keyword arguments. The * and ** are used to pass the no. of args in a function in Python.

Arguments passed as special symbols are:

• **kwargs (non-keyword arguments)
• *args (keyword arguments)

*Args in Python

The *Args is used to grant us to pass the number of non-keyword arguments to function and it is a special signature function in Python. *Args is used to pass variable length argument list and non-keyword.

• The signature is to use * to receive number of arguments.
• The *args is used to add more number of arguments
• If parameter is already used and we need to add extra arguments to that parameter with the help of *Args, we can do it.
• We can do multiply functions with the help of *args.
• Using the *, we can perform some high order functions such as map and filter.

Example for *Args

// Python program to demonstrate *args no of arguments with a variable.


      defmyFun(*argv):
      for i inargv:
        print(i)
 
myFun ('Hey', 'Welcome', 'to', 'javatpoint')

Output:

Hey
Welcome
to
javatpoint

Example 2:

// Python program to demonstrate *args
defmyFun (arg1, *argv):
    print ("First args:", arg1)
    fori inargv:
        print ("Next args through *argv:", i)
 
myFun('Hey', 'Welcome', 'to', 'javatpoint')

Output:

First args: Hey
Next args through *argv: Welcome
Next args through *argv: to
Next args through *argv: javatpoint

**kwargs in Python

*kwargs are used to pass variable length argument list and non-keyword. As we know kwasrgs was used with dual stars, it is used to pass through keyword args.

Example:

// Python program to demonstrate for a variable no. of keywords arguments.
defmyFun(**kwargs):
    forkey, val inkwargs.items():
        print("%s == %s"%(key, val))
// Driver code
myFun(first='java', mid='t', last='point')

Output:

first == java
mid == t
last == point

Example 2:

// Python program to demonstrate a variable number of keywords arguments with one more argument.
defmyFun(arg1, **kwargs):
    forkey, val inkwargs.items():
        print ("%s == %s"%(key, val))
// Driver code
myFun (‘Hey’, first='java', mid='t', last='point')

Output:

first == java
mid == t
last == point

Let’s use both **kwargs and *args to call a function with an argument.

// Python program to demonstrate **kwargs and *args as an argument in the demo function. So, here we are passing both variable length args and place of an argument which are having args.
defmyFun(arg5, arg6, arg7):
    print("arg5:", arg5)
    print("arg6:", arg6)
    print("arg7:", arg7)
 
// Now we can use *args or **kwargs to pass args to this function:
args =("java", "t", "point")
myFun(*args)
 
kwargs ={"arg5": "java", "arg6": "t", "arg7": "point"}
myFun(**kwargs)

Output:

arg5: java
arg6: t
arg7: point
arg5: java
arg6: t
arg7: point

Example 2:

// Python program to demonstrate **kwargs and *args as an args in the demo function.


defmyFun(*args, **kwargs):
    print("args: ", args)
    print("kwargs: ", kwargs)
 
// Now we can use both *args, **kwargs to pass args to this function:
myFun ('java', 't', 'point', first="java", mid="t", last="point")

Output:

args: ('java', 't', 'point')
kwargs {'first': 'java', 'mid': 't', 'last': 'point'}